SE/30 does not boot from SCSI, but drives are accessible

[craig1410]

@timtiger to test the 1Hz pulse, you just need to use the multimeter in DC (not AC) mode and in a voltage range greater than 5V. The multimeter will tend to react quite slowly so you might see it switch between around 4 volts and 1 volts. The important thing isn’t the voltage but the fact it changes roughly every 0.5 seconds between high and low.

Re your snooper test, I wonder if you’ve got some issues with the RAM multiplexers rather than the RAM itself.

Re the Rominator, beware that the PCB might be a bit thinner than the stock ROM and so it might need some extra support to get good connections with the socket. I’ve personally never had an issue with this but some people use 3D printed clips or rubber bands etc. Also be aware that you need to make some changes to system software in order to boot System 7.5 with the Rominator.

It seems to me that you may have more than one issue going on here which always makes it challenging to fix.

 

[Bolle]

And it was indeed the PRAM/RTC chip that was causing the issues.
@timtiger sent me the board, I desoldered the RTC to test it on one of my boards and the fault moved with it.

 

[LaPorta]

Finding RTCs is pretty hard, isn't it.

 

[timtiger]

This week the board arrived back home and works like a charm - thanks for your help guys and @Bolle!

 

[schampango]

I have exactly the same problem, was the solution to replace the RTC?

 

[timtiger]

I have exactly the same problem, was the solution to replace the RTC?

Hi @schampango - yes, in my case the solution was to replace the rtc. Since that the se/30 still works without interruption. Though finding rtc chips isn’t easy; maybe you or someone else has a donator board…

 

[schampango]

Thank you @timtiger for your quick response. That will help me a lot!